Either mild taper-crimp or none atall should be OK, most seater dies will also TC (as well) all in one operation.
To use a FLS die to taper-crimp will need another press operation, but it is possible with care. ( ...but without the decapper stem of course!)

Some accuracy and reliability is claimed for taper-crimping but it depends a lot on the tolerances of your individual pistol/projectiles/cases whether it is worth it. Try 10 or so rounds and then try it on the range.

I leave the mild belling on my own .40S&W cases(6.7gn of W540 with lead 155gn SWC proj ) as they are still a drop-in fit in the chamber (with or without) and the more positive headspace stop /"cleaning action" of the nonTC round may be an advantage if a lot of rounds are fired, but my tests are still continuing on that!